export function getMimeTypeByFileName(fileName) {
    const ext = fileName.split('.').pop().toLowerCase();
    const map = {
      pdf: 'application/pdf',
      doc: 'application/msword',
      docx: 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
      xls: 'application/vnd.ms-excel',
      xlsx: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
      ppt: 'application/vnd.ms-powerpoint',
      pptx: 'application/vnd.openxmlformats-officedocument.presentationml.presentation',
      txt: 'text/plain',
      zip: 'application/zip',
      rar: 'application/x-rar-compressed',
      mp4: 'video/mp4',
      mp3: 'audio/mpeg',
      jpg: 'image/jpeg',
      jpeg: 'image/jpeg',
      png: 'image/png',
    };
    return map[ext] || '*/*';
  }
  